The present invention relates to apparatus for handling foundry sand cores and more particularly relates to hoist-hung devices which can be clamped on or otherwise secured to a core requiring handling during the process of preparing the core for placement in a mold.
In order to improve the finish on casting surface, cores are often coated or washed with a refractory slurry which is then dried onto the core surface. One way of applying the wash to the core is by dipping the core in a vat containing the slurry. The afore-mentioned hoist-hung devices are used to perform the dipping function and the devices are often provided with structure whereby the core may be rotated either manually or mechanically after being dipped so that excess wash drains from the upper surfaces of the core.
A known hoist-hung device having provision for manually rotating a core includes a pair of limbs which straddle the core and are provided with fixtures which engage opposite sides of the core and define a pivot axis about which the core may be rotated. Two people, one grasping each limb, are required to manually engage and flip or turn over the core between the limbs. This can be a difficult and dangerous practice, especially when handling cores having a large mass which becomes unbalanced relative to the pivot axis when the core is being turned over since the core may slip from the control of the workers and cause injury to them as it falls out of control. Also, the core can be damaged under these circumstances.
Another drawback of this known hoist-hung device is that it is more or less dedicated to handling a single family of cores because of the spacing of the limbs and the need to engage opposite sides of the cores.
Some of the drawbacks of the above-described devise; i.e, the requirement for two people, manual roll over and the danger or possible core damage associated with the manual roll over operation, are overcome by known devices which include power means for pivoting or rolling over the core. One such known device includes a pair of double acting, air-operated vane type actuators located on opposite sides of and having respective output shafts connected to an arbor structure for swinging the latter through 90.degree., the arbor structure being engageable with a core so as to swing the latter with it. This device has the disadvantages of being dedicated to handle only one core and thus not being adaptable for having different core-engaging attachments secured thereto and of being swingable only up to 90.degree..